M. M. Barna, L. S. Barna, N. V. Herts, O. B. Matsiuk
Ternopil Volodymyr Hnatiuk National Pedagogical University
DOUBLE FERTILIZATION IN ANGIOSPERMS: HISTORICAL OUTLINE AND SIGNIFICANCE OF THE DISCOVERY BY S.NAVASHYN, PROFESSOR OF ST.VOLODYMYR UNIVERSITY (DEDICATED TO 120TH ANNIVERSARY)
The most outstanding achievement in the botanical science of the 2nd half of the 19th century was the discovery of double fertilization in the flowering plants (Angiosperms), made in 1898 by the professor of St. Volodymyr University, Serhii Havrylovych Navashyn. First the report entitled “Recent Observations about Fertilization in Fritillaria Tenella and Lilium Martagon” was presented on November 24th, 1898 at the 10th Congress of Russian Natural Scientists and Physicians, held in Kyiv. The biological nature of double fertilization involves two sperms, which form in the pollen tube. One of them merges with the ovicell; the other, with the nucleus of the embryo sac, so that both the embryo and the endosperm develop as a result of the sexual process. The discovery of double fertilization by S. Navashyn got further acclaim and became known as a universal law observed in all the flowering plants (angiosperms). However, for some unknown reasons the research studies into the plant embryology in major Ukrainian institutions (located in Kyiv, Odessa, Kharkiv, Poltava, etc.) were suspended. Hopefully, the time will come to resume the research on the plant embryology of flowering plants conducted in Botanical Gardens in Yalta, Uzhhorod National University and Ternopil Volodymyr Hnatiuk National Pedagogical University. Cytoembryologic research should be facilitated and promoted since it is essential for the world science to develop the theory of systematics, phylogeny and plants evolution, and solve issues of incompatibility in the processes of top crossing and interbreeding, as well as forecasting of heterosis in hybrids and cultivars in species of Роpulus L., Sаliх L. genera of Salicaceae Mirb. family, of genus Acer L. of Aceraceae Juss. family, genus Juglans L. of Juglandaceae А. Riсh. eх Kunth family, genus Quercus L. of Fagaceae Dumort family and many other genera and families. The application of innovative research methods (genetic, cytological, cytochemical, histological, biochemical, electromicroscopic, etc.) will enable a more thorough study of specific mechanisms and phenomena (e.g., to examine sperms in the cytoplasm of embryo sac to refer to male elements as nucleuses or cells) of a complex biological process – double fertilization, typical of a division of the Angiosperms (in accord with current terminology Flowering plants (Magnoliophyta). Hopefully, the concerns raised in this extract will encourage cytoembryologic research in Ukraine as it is an essential prerequisite for successful development of Ukrainian and world of Botanical Science.
Keywords: S. Navashyn, double fertilization, chalazogamy, Angiosperms, 10th Congress of Russian Natural Scientists and Physicians, Fritillaria tenella, Lilium martagon